Electrolytic diaphragm cell

ABSTRACT

A diaphragm cell for the electrolysis of aqueous salt solutions in which the cylindrical horizontal cell body is supported at one end by the cathode plate and at the opposite end by the anode plate. At least one anode and at least one cathode are attached to their respective plates in a manner which permits brine to encircle and pass between the electrodes. The cell body may be constructed of a light-weight material such as fiber reinforced plastic. Entry to the cell is facilitated by the horizontal arrangement. The resulting diaphragm cell permits a considerable savings in material and construction costs, reduces cell weight while providing improved brine circulation within the cell.

United States Patent Kircher et al.

Aug. 5, 1975 Assignee:

Filed:

Canada; Elmer N. Macken, Stamford, Conn.

Olin Corporation, New Haven,

Conn.

Oct. 31, 1973 Appl. No.: 411,327

Primary E.\'aminerl-loward S. Williams Assistant Examiner-W. 1. SolomonAttorney, Agent, or Firm.lames B. l-laglind; Donald F. Clements; T. P.ODay [57] ABSTRACT A diaphragm cell for the electrolysis of aqueous saltsolutions in which the cylindrical horizontal cell body is supported atone end by the cathode plate and at the opposite end by the anode plate.At least one anode and at least one cathode are attached to theirrespective plates in a manner which permits brine to encircle and passbetween the electrodes.

The cell body may be constructed of a light-weight material such asfiber reinforced plastic. Entry to the cell is facilitated by thehorizontal arrangement. The resulting diaphragm cell permits aconsiderable savings in material and construction costs, reduces cellweight while providing improved brine circulation within the cell.

16 Claims, 6 Drawing Figures [52] US. Cl. 204/252; 204/266; 204/286 [51]Int. Cl B0lk 3/10 [58] Field of Search 204/252, 266, 286

[56] References Cited UNITED STATES PATENTS 3,133,872 5/1964 Miller eta1 204/290 F X 3,477,938 11/1969 Kircher 204/266 3.679.568 7/1972Westerlund 204/256 X 3,755,108 8/1973 Raetzsch et al.. 204/256 X3.761.385 9/1973 Ruthel et a1 204/290 F 1 II l SHEET PATENTED 5|975PATENTEU AUB 51975 SHEET ELECTROLYTIC DIAPHRAGM CELL This inventionrelates to electrolytic cells for the electrolysis of aqueous saltsolutions. More particularly this invention relates to diaphragm typeelectrolytic cells for the electrolysis of aqueous alkali metal chloride solutions.

Diaphragm-type electrolytic cells are widely used in industry,particularly in the production of chlorine and caustic soda by theelectrolysis of sodium chloride brines. Most of these commercial cellsconsist ofa rectangular structure having a top section and a bottomsection. The cell bodies are constructed of heavy, loadbearing materialssuch as cement or concrete with the anode mounted vertically in thebottom section. The anode is attached to metallic conductors and securedby a layer oflead which is in turn covered by a layer of cement. Thecathode is mounted in the top section or on a side wall.

In diaphragm cells where the anode has been mounted in a side wall, asfor example in US. Pat. Nos. 3,477,938 or 3,247,090, the cell body hasbeen constructed of a load-bearing material such as concrete.

Brine circulation in diaphragm cells of the prior art has beenrestricted generally to flowing on top of or below and between theelectrode sections. Brine has not been free to circulate completelyaround the electrodes.

Therefore, there is a need for a diaphragm electrolytic cell which canbe fabricated from light-weight materials of construction givingsignificant reduction in cost. In addition, there is need for adiaphragm electrolytic cell having improved electrolyte circulationwhich permits brine circulation completely around and thru the electrodesection.

It is an object of the present invention to provide a diaphragm cellwhich can be readily fabricated at a reduced cost and having reducedweight.

Another object of the invention is to provide a diaphragm cell having acathode attached to a conductive end wall and an anode attached to anopposite conducting end wall.

A further object of the invention is a diaphragm cell having improvedelectrolyte circulation.

Yet another object of the present invention is to provide a diaphragmcell wherein the cell body is supported by the conductive end walls.

An additional object of this invention is to provide a horizontaldiaphragm cell having entries to the cell body thru the ends.

A still further object of the invention is to provide a horizontaldiaphragm cell having a shorter and more direct current path through thecell and between adjacent cells.

These and other objects of the invention are accomplished in anelectrolytic diaphragm cell comprised of a horizontal cell body havingopposite and substantially parallel ends, having a first opening at oneend of the cell body and a second opening at the opposite end of thecell body. An electroconductive cathode plate is sealingly attached tothe cell body and covers the first opening. The cathode support has atleast one cathode attached to the inner surface of the cathode plate.

An electroconductivc anode plate is sealingly attached to the cell bodyand covers the second opening. The anode plate has at least one anodeattached to the inner surface of the anode plate. The cathode plate andthe anode plate support the cell body.

Accompanying FIGS. 1-6 illustrate the novel cell of the presentinvention. Corresponding parts have the same numbers in all FIGS.

FIG. 1 illustrates a side view of one embodiment of the diaphragm cellof the present invention.

FIG. 2 shows a partially sectioned top view of the diaphragm cell ofFIG. 1.

FIG. 3 depicts an end view of the diaphragm cell of FIG. 1 showing thecathode plate.

FIG. 4 is a top view of the cathode section of the diaphragm cell ofFIG. 1.

FIG. 5 illustrates a top view of the anodesection of the diaphragm cellof FIG. 1.

FIG. 6 is a cross sectional view of the diaphragm cell of FIG. 1 takenalong lines 6-6.

Apparatus described in FIGS. l-6 when used to electrolyze aqueoussolutions of alkali metal halides form halogen gas, hydrogen gas and analkali metal hydroxide liquor. However, those skilled in the art willrecognize that modifications can be made for the use of other startingmaterials to produce other products.

More in detail, FIG. 1 is a side view of one embodiment of the inventionillustrating diaphragm cell A having ,a horizontal generally cylindricalcell body I and having flanges 2 and 3 surrounding each opening at theends of cell body 1. Anode plate 4 is attached to flange 2 at one end ofcell body 1 and cathode plate 5 is attached to flange 3 at the other endof cell body 1. Gas kets 6 and 7 seal anode plate 4 to flange 2 andcathode plate 5 to flange 3, respectively.

An aqueous alkali metal halide solution to be electrolyzed enters thrubrine inlet 12 housed in cell body 1. Halogen gas is removed throughhalogen outlet 10, and hydrogen gas is removed through outlet 11.Electric current is introduced to the cell through conductor 13 attachedto anode plate 4. Current is removed from the cell at conductor 14attached to cathode plate 5.

Cathode plate 5 and anode plate 4 support the weight of cell body 1.Anode plate supports 8 bear the weight of anode plate 4 and cathodeplate supports 9 uphold cathode plate 5. Anode plate supports 8 andcathode plate supports 9 are bolted or otherwise attached to insulators23 resting on platforms 24.

Drain l5 permits the contents of the cell to be removed. Lugs 16 and 17aid in the removal of conductive anode plate 4 and conductive cathodeplate 5, respectively.

FIG. 2 depicts a partially sectioned top view of diaphragm cell A of thepresent invention. Anodes 21 are attached to anode plate 4 and projectacross the cell toward cathode plate 5. Cathodes 22 are attached tocathode plate 5 and project across the cell towards anode plate 4.Cathodes 22 support a diaphragm (not shown) of the type described morefully below. Anodes 21 are inserted within the spaces between adjacentcathodes 22. Current enters the cell thru conductor 13 andflows thruanode plate 4, thru anodes 21 attached, thru the electrolyte betweenanodes 21 and cathodes 22 and thru cathodes 22 to cathode plate 5.Current leaves the -cell thru conductor 14 attached to cathode plate 5.Thus, the current passes thru the cell in a short and direct path.Conductors 13 and 14 have a series of holes permitting these conductorsto be attached to conductors on adjacent cells, for example, with bolts.

FIG. 3 shows an end view partially sectioned of diaphragm cell A of thepresent invention. Cathode plate 5 is attached to cell body 1 (notshown) by a series of bolts 25 spaced equidistantly around theperiphery. Cathode plate supports 9 provide support for cathode plate 5.Cathodes 22 are attached to and spaced apart from the outer edges ofcathode plate 5. Conductor l4 removes current from cathode plate 5. Anaqueous alkali metal halide solution is introduced into the cell thrubrine inlet 12. Hydrogen gas produced during electrolysis is removedthru hydrogen outlet 11 and the alkali metal hydroxide liquor producedis removed through outlet 20.

A top view of cathode section 28 of diaphragm cell A is depicted in HO.4. Cathodes 22 are comprised of a conductive element 26 attached to andproviding support for the surrounding screen 27. Cathodes 22 areattached to cathode plate 5, being parallel to and separated from eachother to form cathode section 28. Cathode section 28 is spaced apartfrom the perimeter of cathode plate to permit brine to encircle thecathode section.

FIG. 5 is a top view of anode section 29 of diaphragm cell A. Anodes 21are attached to anode plate 4 and are parallel to and separated fromeach other to form anode section 29. Anode section 29 is spaced apartfrom the perimeter of anode plate 4 to permit brine to encircle theanode section.

FIG. 6 shows a cross-sectional view taken along lines 6-6 of FIG. 1.Anode plate 4 has a plurality of anodes 21 attached to form anodesection 29. Cathodes 22, attached to cathode plate 5 (not shown) arearranged so that an anode is inserted between and is substantiallyequidistant from each adjacent cathode. Anode section 29 is spaced apartfrom the perimeter of anode plate 4 to permit electrolyte to encirclethe anode section.

The horizontal cell body of the electrolytic diaphragm cell of thepresent invention may be of any convenient configuration, for example,it may be rectangular, cylindrical or elliptical. Preferably, it isgenerally cylindrical or elliptical. The cell body may be constructed ofa variety of materials, such as, fiber reinforced plastic, hard rubber,steel, hard rubber-lined steel, titanium, asbestos reinforced plastic orconcrete. In one embodiment the cell body comprises a cylindrical shellof fiber reinforced plastic wherein the fiber is, for example,fiberglass and the plasticis, for example, a polyester or epoxy resin. Acell body of this type can be fabricated easily, for example, on amandrel using filament winding techniques to form a cell body havingreduced weight and having high body strength. Additional embodiments maycomprise a shell of steel or concrete lined with a protective coatingsuch as rubber, ceramic tile composites, plastics reinforced withasbestos, carbon, silica, or glass flakes, or polyhaloolefin plasticssuch as polytetrafluoroethylene or polychlorotrifluoroethylene.

The cell body may be of any convenient height. For example, a cell bodyof from about 1 to about 15, and preferably from about 4 to about 12feet may be employed. To facilitate attachment of the electrode plates,the cell body may have a flange surrounding the opening at each end.

The anode plate attached to one end of the cell body, is wholly orpartially constructed of an electroconductive material such as steel,copper, aluminum, titanium or combinations of these materials. Where theelectroconductive material can be attacked by the solution or gases inthe cell it can be covered, for example, with rubber, a chemically inertplastic such as polytetrafluoroethylene or fiber reinforced plastic or ametal such as titanium or tantalum.

In a preferred embodiment, the anode plate is composed of steel which islined with rubber on the inner surface. The steel serves both as anelectroconductor and a structural material which has sufficient strengthto support the cell body without requiring an excessive mass ofmaterial.

The anode support plate is attached at one opening of the cell body byany convenient attachment means such as bolts, tie rods or clamps.

A series of bolts are used in one embodiment of the present invention toattach the anode plate to the cell body. The bolts, placed around theperiphery of the plate, facilitate the uniform allignment of anodes whenthe cell is assembled. The anode plate supports at least one anode.

Anodes suitable for use in this invention are composed of graphite, avalve metal such as titanium or tantalum, or a metal, for example,steel, copper or aluminum clad with a valve metal such as tantalum ortitanium. The valve metal has a thin coating over a least part of itssurface of platinum group metal, platinum group metal oxide, an alloy ofa platinum group metal or a mixture thereof. The term platinum groupmetal" as used in the specification means an element of the groupconsisting of ruthenium, rhodium, palladium, osmium, iridium andplatinum.

Anodes can be made in various forms, for example, solid sheets,perforated plates and in the case of conductive metal, as expanded metalor screen. The anodes are attached to the anode support plate bybolting, welding, soldering, or the like.

The anodes employed may be any convenient size, for example, from about1 to about 12, and preferably from about 2 to about 1() feet in height;from about I to about 6, and preferably, from about 2 to about 5 feet inlength; and from about 0.05 to about 1.00, and preferably from about 0.lto about 0.8 inches thick.

A plurality of anodes are attached to the anode plate, the exact numberdepending on the size of the anode plate. In the diaphragm cell of thepresent invention, for example. from about 2 to about or more, andpreferably from about 5 to about 50 anodes are attached to the anodeplate and constitute the anode section. The anodes are positionedparallel to and separated from each other on the anode plate. The anodesection is attached to the anode plate in such a manner that it isspaced apart from the perimeter of the anode plate, as illustrated inFIG. 6. This arrangement permits brine to flow completely around theanode section as well as up through the spaces between the anodes.

The cathode plate is composed wholly or partly of an electroconductivematerial, for example, steel or copper or combinations of thesematerials. To avoid corrosive damage the cathode plate may be covered,for example, with hard rubber, a plastic such as polytetrafluoroethyleneor fiber reinforced plastic.

A preferred embodiment is a cathode plate composed of hard rubber linedsteel. The steel serves both as an electroconductive metal and astructural material able to support the cell body without requiring anexcessive mass of material. The use of steel is economic as it can. ifdesired, eliminate entirely the requirement for more expensiveconductors such as copper. The cathode plate is sealingly attached atone opening of the cell body in anyconvenient manner, for example.

by bolts, tie rods or clamps. in one embodiment, the cathode plate isattached to the cell body by a series of bolts spaced around theperiphery of the plate. The bolts assure an accurate and simplifiedalignment of the cathodes when the cell is assembled.

A plurality of cathodes are attached to the cathode plate, the exactnumer depending on the size of the cathode plate. In the diaphragm cellof the present invention, for example, from about 2 to about 100 or moreand preferably from about 5 to about 50 cathodes constitute the cathodesection. The cathodes are positioned parallel to and separated from eachother on the cathode plate.

The cathodes are foraminous projections extending across the cell bodytoward the anode support plate. A single cathode comprises a conductiveelement surrounded by a conductive screen or mesh. The conductiveelement may be, for example, in the form of a plate or rod withattachment means for the screen or mesh. In one embodiment of thediaphragm electrolytic cell of the present invention, the conductiveelement is a steel plate having projections at spaced intervals alongthe plate. The projections are attached to the cathode screen to providesupport and to supply current to the cathode screen. The projections maybe made, for example, by punching or stamping the conductive plate.Cathodes are attached to the cathode plate by any suitable means, forexample, by welding or bolting.

The cathodes may be of any convenient size, for example, from about 1 toabout 12, and preferably from about 2 to about feet in height; fromabout I to about 6 and preferably from about 2 to about 5 feet inlength; and from about 0.5 to about 2.0 and preferably from about 0.8 toabout 1.5 inches thick.

In the diaphragm cell of the present invention, the anode and cathodeplates support the weight of the cell body. The anode and cathode platesmay support the cell body directly by having a perimeter larger thanthat of the cell body whereby the weight of the cell rests directly onthe anode and cathode plates. In another embodiment, the anode andcathode plates are each attached at the lower edge to at least onesupport, for example, a bracket, brace, or strut. The anode and cathodeplate supports are suitably insulated to prevent current loss.

In the use of the present apparatus as a diaphragm cell, anyconventional inert diaphragm material is applied or deposited on thecathodes. The diaphragm material which can be used to cover the screenor foraminous portion of the cathode is a fluid-permeable andhalogen-resistant material. Preferably the material is asbestos fiberdeposited on the outer surfaces of the cathode screen by the applicationof suction to an asbestos fiber slurry. Other diaphragm materials suchas polyvinylidene chloride, polypropylene, or polytetrafluoroethylenemay also be used. The cathode structure is adapted to permit the use ofall types of diaphragms including sheet asbestos, deposited asbestos andsynthetics which can be in the form of woven fabrics, for example.polyethylene, polypropylene 0r polytetrafluoroethylene.

In the assembled diaphragm cell of the present invention. the cathodesection is positioned so that the cathodes project across the cell bodyin the direction of the anode support plate. The anode section isoppositely positioned such that the anodes project across the celltowards the cathode plate, with the anodes being inserted betweenadjacent cathodes. The distance between an anode and the adjacentcathode is normally between about one-eighth to about three-eighths ofan inch.

The diaphragm cell of the present invention may utilize anode andcathode plates of variable height. For example, anode and cathode platesof from about 1 to about 15 and preferably from about 4 to about 12 feethigh may be employed. Increasing the height of the diaphragm cellpermits a considerable reduction in the floor space required to producea given quantity of product.

In the operation of the diaphragm cell of the present invention, anaqueous salt solution, for example, an alkali metal chloride such assodium chloride or potassium chloride, may be employed. The alkali metalchloride solution is introduced into the cell as a brine stream of anydesired concentration. The brine level within the cell is brought to apoint above the anode and cathode sections within the cell. By adjustingthe level within the cell the hydrostatic head or pressure exerted uponthe diaphragm covering the cathodes is varied, thereby varying the flowof electrolyte through the diaphragm into the cathode chamber. Undernormal operating conditions the height of the brine above the anode andcathode sections is from about 3 to about 15 or more inches.

The anode and cathode sections are spaced apart from the perimeter oftheir respective plates to provide greatly improved brine circulationwithin the cell. Preferably the anode and cathode sections are centeredlaterally. They are positioned vertically such that an adequate brineheight and gas release space is provided above the anode and cathodesection. In addition to permitting brine to flow completely around theanodes and cathodes, the space above the electrode sections permits afree release of gas produced in the anode. Without being bound bytheory, it is believed that when chlorine gas forms at the anodes andrises, it creates a gas lift action directed vertically along the faceof the anodes. This gas lift action draws fresh brine from below theelectrode sections, with the fresh brine then flowing upward along theanodes into the region above the anodes, at which point chlorine gasleaves the brine. The heavier brine, from which chlorine gas has beenpartially exhausted, flows laterally above the electrode sections andthen downward along the outside edges of the electrode sections.

Current capacities of from about 1,000 to about 300,000 and preferablyfrom about 10,000 to about 200,000 amps, may be employed inelectrolyzing aqueous salt solutions in the diaphragm cell of thisinvention.

The following example is presented to illustrate the invention morefully. All parts and percentages are by weight unless otherwiseindicated.

EXAMPLE A diaphragm cell, as illustrated in FIGS. l-6, was comprised ofa horizontal cylindrical cell body composed of glass fiber reinforcedpolyester resin and having an outside diameter of about 92 inches. Aflange surrounded the openings at each end of the cell body. At one endof the cell a cathode plate was bolted to the flange of the cell body.The cathode plate, composed of mild steel and covered with rubber on theinside face, had an outside diameter of about 96 inches. The

cathode section was comprised of 27 cathodes, each cathode being weldedto the cathode face. A cathode included a steel plate having a series ofprojections to which a steel screen was attached. Deposited on thescreen was an asbestos fiber diaphragm. The cathodes were about 36inches long, inches high, and 1.125 inches thick and were spaced at adistance of 2.5 inches between centers. The cathode section was spacedat a distance of about 33 inches from the upper and lower perimeters andabout 14 inches from the lateral perimeters of the cathode plate.

At the opposite end of the cell body an anode plate was bolted to theflange. The anode plate was about 96 inches in diameter and was composedof mild steel with the inside face being covered with rubber. The anodesection had 28 anodes soldered to the anode plate. Each anode wascomposed of titanium-clad steel and had a portion of its surface coatedwith a ruthenium oxide. The anodes were about 36 inches long, 30 incheshigh and 0.18 inch thick and spaced apart 2.5 inches between centers.The anode section was spaced at a distance of about 33 inches from theupper and lower perimeters and about 14 inches from the lateralperimeters of the anode plate. The cathode plate and the anode platewere each externally supported by a steel bracket welded to the plate.The cathode and anode plates supported the weight of the cell body.

An aqueous solution containing 300 grams per liter of sodium chloride ata temperature of about 60-70C. was introduced into the cell body thruthe brine inlet in the cathode plate. The cell operated at a current of76 kiloamperes and a voltage of 3.78 to electrolyze the salt solution toproduce chlorine, hydrogen and sodium hydroxide. The catholyte liquorobtained had a sodium hydroxide concentration of about 125 grams perliter. The chlorine gas obtained had a hydrogen content of 0.3 percent.Over a period of 106 hours, the cell was operated at a currentefficiency of 97 percent, based on chlorine production.

What is claimed is:

1. An electrolytic diaphragm cell comprised of a. a horizontal cell bodyhaving opposite and substantially parallel ends, having a first openingat one end of said cell body and a second opening at the opposite end ofsaid cell body;

b. an electroconductive cathode plate sealingly attached to said cellbody and covering said first opening, said cathode plate having at leastone cathode attached to the inner surface of said cathode plate;

c. an electroconductive anode plate sealingly attached to said cell bodyand covering said second opening, said anode plate having at least oneanode attached to the inner surface of said anode plate; and

d. said cathode plate and said anode plate providing the sole means ofsupport for said cell body.

2. The electrolytic diaphragm cell of claim 1 in which said cell body iscylindrical in shape.

3. The electrolytic diaphragm cell of claim 2 in which said cell body iscomprised of a material of construction selected from the groupconsisting of steel, concrete, fiber reinforced plastic, hard rubber,asbestos reinforced plastic, or titanium.

4. The electrolytic diaphragm cell of claim 3 in which said cell body iscomprised of a shell of a material selected from the group consisting ofsteel or concrete.

5. The electrolytic diaphragm cell of claim 4 in which said shell has alining material selected from the group consisting of fiber reinforcedplastic, rubber, asbestos reinforced plastic, ceramic tile composites,polytetrafluoroethylene, or polychlorotrifluoroethylene.

6. The electrolytic diaphragm cell of claim 5 in which said cathodeplate is a metal selected from the group consisting of steel or copper.

7. The electrolytic diaphragm cell of claim 6 in which said cathode isspaced apart from the perimeter of said cathode plate.

8. The electrolytic diaphragm cell of claim 7 in which said anode plateis a metal selected from the group consisting of steel, copper,aluminum. or titanium.

9. The electrolytic diaphragm cell of claim 8 in which said anode is avalve metal selected from the group consisting of titanium or tantalumhaving at least part of its surface coated with a coating selected fromthe group consisting of a platinum metal, platinum metal oxide, platinummetal alloy or mixtures thereof.

10. The electrolytic diaphragm cell of claim 9 in which said anodecomprises a metal selected from the group consisting of steel. copper oraluminum, said metal being clad with said valve metal.

11. The electrolytic diaphragm cell of claim 10 in which said anode isspaced apart from the perimeter of said anode plate.

12. The electrolytic diaphragm cell of claim 1 in which a flangesurrounds each of said first openings and said second opening.

13. The electrolytic diaphragm cell of claim 1 in which the perimeter ofeach of said cathode plate and said anode plate is greater than saidcell body.

14. The electrolytic diaphragm cell of claim 13 in which said cell bodyis elliptical in shape.

15. The electrolytic diaphragm cell of claim 1 in which said cathodeplate and said anode plate each have at least one support attached tothe external side of said plate.

16. An electrolytic diaphragm cell for the electrolysis of aqueousalkali metal chloride solutions comprised of:

a. a cylindrical cell body horizontally arranged having opposite andsubstantially parallel ends, having a first opening at one end of saidcell body and a second opening at the opposite end of said cell body;

b. an electroconductive cathode plate sealingly attached to said cellbody and covering said first opening, said cathode plate having aperimeter greater than that of said cell body, said cathode plate havinga cathode section attached to the inner surface of said cathode plate,said cathode section comprising a plurality of cathodes, said cathodesection being spaced apart from said perimeter of said cathode plate;

c. an electroconductive anode plate sealingly attached to said cell bodyand covering said second opening, said anode plate having a perimetergreater than that of said cell body, said anode plate having an anodesection attached to the inner surface of said anode plate, said anodesection comprising a plurality of anodes, said anode section beingspaced apart from said perimeter of said anode plate; and H d. saidcathode plate and said anodeplate providing sole means for supportingsaid cell body.

1. AN ELECTROLYTIC CELL COMPRISED OF A. A HORIZONTAL CELL BODY HAVINGOPPOSITE AND SUBSTANTIALLY PARALLEL ENDS, HAVING A FIRST OPENING END OFSAID CELL BODY AND A SECOND OPENING AT THE OPPOSITE END OF THE CELLBODY, B. AN ELECTROCONDUCTIVE CATHODE PLATE SEALINGLY, ATTACHED TO SAIDCELL BODY AND COVERING SAID FIRST OPENING, SAID CATHODE PLATE HAVING ATLEAST ONE CATHODE ATTACHED TO THE C. AN ELECTROCONDUCTIVE ANODE PLATESEALINGLY ATTACHED TO SAID CELL BODY AND COVERING SAID SECOND OPENING,SAID ANODE PLATE HAVING AT LEAST ONE ANODE ATTACHED TO THE INNER SURFACEOF SAID ANODE PLATE, AND D. SAID CATHODE PLATE AND SAID ANODE PLATEPROVIDING THE SOLE MEANS OF SUPPORT FOR SAID CELL BODY.
 2. Theelectrolytic diaphragm cell of claim 1 in which said cell body iscylindrical in shape.
 3. The electrolytic diaphragm cell of claim 2 inwhich said cell body is comprised of a material of construction selectedfrom the group consisting of steel, concrete, fiber reinforced plastic,hard rubber, asbestos reinforced plastic, or titanium.
 4. Theelectrolytic diaphragm cell of claim 3 in which said cell body iscomprised of a shell of a material selected from the group consisting ofsteel or concrete.
 5. The electrolytic diaphragm cell of claim 4 inwhich said shell has a lining material selected from the groupconsisting of fiber reinforced plastic, rubber, asbestos reinforcedplastic, ceramic tile composites, polytetrafluoroethylene, orpolychlorotrifluoroethylene.
 6. The electrolytic diaphragm cell of claim5 in which said cathode plate is a metal selected from the groupconsisting of steel or copper.
 7. The electrolytic diaphragm cell ofclaim 6 in which said cathode is spaced apart from the perimeter of saidcathode plate.
 8. The electrolytic diaphragm cell of claim 7 in whichsaid anode plate is a metal selected from the group consisting of steel,copper, aluminum, or titanium.
 9. The electrolytic diaphragm cell ofclaim 8 in which said anode is a valve metal selected from the groupconsisting of titanium or tantalum having at least part of its surfacecoated with a coating selected from the group consisting of a platinummetal, platinum metal oxide, platinum metal alloy or mixtures thereof.10. The electrolytic diaphragm cell of claim 9 in which said anodecomprises a metal selected from the group consisting of steel, copper oraluminum, said metal being clad with said valve metal.
 11. Theelectrolytic diaphragm cell of claim 10 in which said anode is spacedapart from the perimeter of said anode plate.
 12. The electrolyticdiaphragm cell of claim 1 in which a flange surrounds each of said firstopenings and said second opening.
 13. The electrolytic diaphragm cell ofclaim 1 in which the perimeter of each of said cathode plate and saidanode plate is greater than said cell body.
 14. The electrolyticdiaphragm cell of claim 13 in which said cell body is elliptical inshape.
 15. The electrolytic diaphragm cell of claim 1 in which saidcathode plate and said anode plate each have at least one supportattached to the external side of said plate.
 16. An electrolyticdiaphragm cell for the electrolysis of aqueous alkali metal chloridesolutions comprised of: a. a cylindrical cell body horizontally arrangedhaving opposite and substantially parallel ends, having a first openingat one end of said cell body and a second opening at the opposite end ofsaid cell body; b. an electroconductive cathode plate sealingly attachedto said cell body and covering said first opening, said cathode platehaving a perimeter greater than that of said cell body, said cathodeplAte having a cathode section attached to the inner surface of saidcathode plate, said cathode section comprising a plurality of cathodes,said cathode section being spaced apart from said perimeter of saidcathode plate; c. an electroconductive anode plate sealingly attached tosaid cell body and covering said second opening, said anode plate havinga perimeter greater than that of said cell body, said anode plate havingan anode section attached to the inner surface of said anode plate, saidanode section comprising a plurality of anodes, said anode section beingspaced apart from said perimeter of said anode plate; and d. saidcathode plate and said anode plate providing sole means for supportingsaid cell body.